Thread tensioning device



Dec. 3, 1940. H H BURDETT 2,224,097

THREAD TENS IONING DEVICE Filed May 13, 1940 `ATTORNEY- Patented Dec. 3,1940 UNITED STATES THREAD TENsIoN'ING DEVICE Horace H. Burdett, Milford,Mass., assignorto Draper CorporatiomHopedale, Mass., a corporation o!Maine Application May 1a, 1940, serial No. 334,804

6 Claims.

This invention pertains to automatically threading loom shuttles and hasmore particular reference to such shuttles having automaticallythreading tension devices for applying tension to the running fillingthread.

Shuttles of the type mentioned are used in bobbin changing looms'wherever the character of filling thread employed or cloth being wovenis such as to require more tension on the filling lo thread than isobtainable with shuttles having simple threading blocks. Of the varioustypes of tension devices heretofore proposed, the spring clamp type,so-called. is to be preferred froml the standpoint of simplicity andruggedness of 5 design and also because of the more uniform tensionwhich it provides.

However, such prior spring clamp tension devices have beenunsatisfactory in that they failed to provide a suiiiciently uniformtension and sumciently fine adjustment of the tension.

.The principal object of the present invention is to provide, in anautomatically threading tension device of the spring clamp type. meanswhereby a. more uniform tension is produced and finer adjustment of thetension is readily obtainable.

Other objects and advantages of the invention will be made manifest inthe following more detailed description of the preferred embodiment ofthe invention and by reference to the accompanying drawing, wherein:

Fig. 1 is a plan View of the thread delivery end of the shuttle;

Fig. 2 is a. view in section as indicated by line 2-2 of Fig. 3; and

Fig. 3 is a view in cross-section taken on line 3-3 of Fis. 2.

The shuttle shown on the drawing is comprised of a shuttle body I havinga cavity 2 for receiving an automatically replaceable filling carriersuch as bobbin, a threading block 4, and a side delivery eye 5. Theshuttle body may be provided with a thread trapping wall 6 as more fullydisclosed in patent to W. I. Stimpson, No. 1,985,960,

granted Jan. 1, 1935.

' The shuttle has a longitudinally extending thread passage 1 which isin alignment with the cavity 2. The thread passage or as much thereof asis in the threading block 4 is defined by the front wall 8 and the rearwall 9 of the threading block.

A guard or horn I0 projects from the front wall 8 outwardly andrearwardly, as in the said Stimpson patent. The term "outwardly" isherein used to mean in a direction from the cavity'2, longitudinauy ofthe shutue toward the up, 1. e. toward the right on Figs. 1 and 2.`Other expressions denoting direction are applicable to the shuttle whenthe same is considered to be positloned in the loom. 5

The shuttle is provided with a tension device, which device may comprisea pair of friction members yieldingly pressed together for exerting aslip-grip upon the running filling. The tension device as shown ispreferably carried by the 10 threading block at theinner end ofthethread passage in the latter, there being a front friction member II anda rear friction member I2. The members II and I2 extend transversely ofthe filling thread and thread passage, preferably at 15 an angle to theperpendicular axis of the threading block 4 as best shown by Fig. 3. l

The particular friction members II and I2 shown on the drawing, may beformed from elongated bodies of fiat steel bent into the shape 20 bestshown by Fig. 3. The upper end of friction member II isprovided with ahorizontally extending guide lug I3 entering into a bushing I4 in arecess I5 in the threading block 4, whereby the friction member ismovably guided and sup- 25 ported. The upper end of friction member i2is provided with a horizontally extending lug IB entering into a.bushing I'l in a recess I8 in the threading block 4, whereby thefriction member is movably guided and supported. The friction 30 membersIl and I2 are provided adjacent their bottom ends with aligned holes I8and 20 respectively for the reception pf supporting means. Thesupporting means shown may comprise an adjustable screw 2| threadedintothe rear wall 35 9 and having a pin 22 projecting from'its forwardend. The pin 22 being received in an opening 23 in the front wall 8, thepin 22 passes through the holes I9 and 20 in the friction members II andI2 and supports said friction members. The in- 40 ner face 24 of thescrew 2l abuts the rear friction member I2. By turning said screw thefriction members II and I2 may be adjusted in 4their relation to theside walls of the thread slot.

'The friction members II and I2 may be yield- 45 ingly pressed togetherby suitable spring means. In the construction shown, member I2 ispressed toward member II by a spring 25 which engages between member I2and an adjusting screw 26 threaded into the rear wall 9 of the threading50 block. Member II is pressed toward member I2 by a spring 2l whichengages between member II and an adjusting screw 28 threaded into thefront wall 8 of the threading block.

An important featureof novelty of the shuttle 55 shown resides in therelative location of the spring means such as 25 and 21. .As best seenon Fig. 3 these springs are staggered in. relation to each other.

5 In the prior types of springclamp tension devices where the tensionmeans are in horizontal axial alignment, there is a tendency for thefriction members to press against the running filling thread with avarying pressure. Starting with l0 slight pressure at the entrance endthe pressure increases up to the point of location of the tension meansand decreases from that point downward to the bottom of the frictionmembers. Thus the pressure exerted by the friction members is notuniform throughout their length. By

vertically spacing the tension means, a more uniform pressure isexterted by the friction members throughout their length. 'I'he innerface 24 of screw 2i acts as an abutment about which members il and l2are moved by tension springs 25 and 21. Spring moves the membersclockwise about the abutment and spring 21 moves the memberscounter-clockwise about the abutment (as viewed on Fig. 3). Due to thefact that 25 spring 25 is located further from the abutment 24 than isspring 21, the pressure exerted by membersl H and I2 againsteach other,and of course against the running liing thread therebetween,

will be substantially uniform throughout their lengths.

' Also by having the adjusting tension means spaced vertically a fineradjustment of the ten-v sion exerted by the friction members can beobtained. Because of their location in relation to the friction membersII and I2, the front and rear tension springs exert a different pressureagainst the filling thread. It has been found that one turn of the backadjusting screw 26 is equal to approximately one halfturn of the front40 adjusting screw 28. 'I'his is very important in obtaining the fineadjustments necessary -for yarns such as rayon of 100 denier and under.

Having thus fully disclosed the preferred embodiment of my invention, Iclaim:

1. An automatically threading loom shuttle.

having a cavity for a filling carrier, a threading block having alongitudinally extending thread passage in alignment with said cavity,and a tension device in said thread passage, said tension devicecomprising a pair of opposed friction members extending transversely ofsaid thread passage said members being laterally movable in relation toeach other 4throughout their lengths and yieldingly pressed together forexerting a slip-grip upon the running filling thread, said tensiondevice being open at one end to thereby provide a thread entrance,yielding means pressing against one of said friction members, a secondyielding means pressing against the other of said o0 friction members,said second yielding means being spaced longitudinally of said membersfrom said first yielding means, and means for adjusting the tension ofsaid yielding means. 2. 'Iyhe combination in a shuttle having a longi-'tudinal threading slot, of two friction members having contactingfriction faces, means located adjacent the top of -said slot for movablysupporting said-members, an adjustable abutment extendingl transverselyof said slot adjacentl the 10 lower end thereof, an adjustable tensionmember located on one side of said friction members and pressing saidfriction members against Isaid abutment, a second adjustable tensionmember located on the other side of said friction members 75 andpressing said friction members away from said abutment, said secondnamed tension member being located substantially twice the distance fromsaid abutment as said first named tension member.' whereby said frictionmembers exert a substantially uniform force against each 5 otherthroughout their length.

3. The combination in a shuttle having a threading block therein, saidblock having a longitudinal threading slot. of two friction membershaving contacting friction faces for tensionl0 -ing the running llingthread therebetween, means` located adjacent the top of said slot forslidably supporting said members, an adjustable member extendingtransversely of said slot adjacent the lower end .thereof for supportingsaid 15 friction members, an abutment carried by said adjustable memberagainst which the lower ends of said friction members rest, a pairof'coiled compression springs for pressing said friction memberstogether, one of said springs being lo- 20 cated a greater distanceabove said abutment than the other whereby said friction members arepressed together with substantially a uniform pressure throughout theirlength.

4. 'I'he combination in a shuttle having a longi- 25 tudinal threadingslot, of two friction plates having contacting friction faces, meanslocated adjacent the top of said slot for movably supporting saidplates, adjustable means located adjacent the bottom of said slot forsupporting said plates 30 and adjusting said plates laterally inrelation to the walls of said slot, vertically spaced yielding meansintermediate said supporting means forl pressing said plates againsteach other and causing the latter to exert a substantially uniform 35slip-grip on the running filling, and means for adjusting the tension ofsaid yielding means.

5. A n automatically threading loom shuttle having a threading slottherein and also having a pair of oppositely disposed recesses adjacentits 10 upper edge, said recesses opening into said slot,

a pair of plates having contacting friction faces for tensioning therunning lling therebetween, each of said plates having a guide lug atits upper end projecting into one of said recesses for slid- 45 ablysuspending said plate in said threading slot,

an adjustable member extending transversely of said slotadjacent thelower end thereof for supporting said plates, said member having anabutment contacting the lower end of one of said 5 plates whereby saidends may be adjusted in relation to the side wallsof said slot, anadjusting screw having resilient means on its forwardA end for pressingone of said plates against theother, and a second adjusting screw havingre- 55 silient means on its rearward end for pressing, the other of saidplates against the plate contacted by said iirst named resilient means,the points of contact of said resilient means with said plates beinglocated at different distances 00V above said `abutment whereby saidplates are pressed' together with a substantially uniform tensionthroughout their length.

6. An automatically threading loom shuttle having a cavity for a fillingcarrier, a threading 55 block having a longitudinally extending threadpassage in alignment with said cavity and also having a pair ofoppositelydisposed recesses adjacentl its upper edge opening into saidthread passage, and a tension device in said thread passage, saidtension device comprising a pair of friction members, each of saidfriction members having a hole adjacent its bottom end and having aguide lug at its upper end projecting into one of said recesses, a screwthreaded into said threading block adjacent the bottom of said threadpassage, said screw having a pin projecting from one end thereof andextending through said openings in said friction members for supportingsaid members, the inner face of said screw forming an adjustableabutment whereby said friction? members are laterally adjustable inrelation to the side walls of said thread passage, a compres-'L sionspring positioned behind each friction member for yieldingly pressingsaid members together to exert a slip-grip upon the running fillingthread, said springs being spaced vertically from each other, and a pairof adjusting screws threaded into said threading block for adjusting thetension of said springs. j

HORACE H. BURDE'I'I.

